Thermal transfer printers are known in which, with an ink ribbon and printing paper being sandwiched between a thermal head and a platen roll, the thermal head applies heat to the ink ribbon to transfer a dye from the ink ribbon onto the printing paper.
In the thermal transfer printers, the ink ribbon thus used in printing has a residual image thereon and information may leak therefrom. For example, in printers for commercial purposes, an ink ribbon used by customers is left inside the in-store printer. The used ink ribbon, which is simply placed inside the printer, can be easily accessed by an administrator of the printer. If the used ink ribbon is simply discarded, print information may leak to outsiders. To prevent leakage of information, the used ink ribbon is required to be subjected to appropriate measures.
For example, a thermal transfer system has been proposed, in which an outermost region of an ink ribbon wound around a take-up unit is fused to another region of the ink ribbon located inside the outermost region. With this thermal transfer system, different regions of the ink ribbon wound around the take-up unit after ink transfer can be joined together. This prevents leakage of printed text and image information from the ink ribbon from which ink has been transferred.
However, the thermal transfer system described above is costly, because it requires two transfer devices: a first transfer device configured to transfer ink from the ink ribbon onto printing paper to print text and images thereon; and a second transfer device disposed near the take-up unit for winding therearound the ink ribbon from which ink has been transferred (i.e., used ink ribbon), and configured to heat a region of the used ink ribbon to fuse it to another region of the used ink ribbon inside the heated region.
PTL 1: Japanese Unexamined Patent Application Publication No. 2013-202802
PTL 2: Japanese Unexamined Patent Application Publication No. 2005-14398